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Dentistry/root canal retreatment


Eight years ago, when she was twelve, my daughter had a root canal on tooth 18 (I think)...the lower back molar. The dentist that did the work said the tooth was fine and did not need a crown.  A couple of months ago, a new dentist in the same office (a national chain) said that the tooth was appearing brittle and would need a crown, but that the root looked like it had abscessed and he wanted it evaluated by an endodontist before he crowned it.  We saw the endodontist today.  He started a new root canal, and was surprised to find that the reason the roots hadn't sealed properly was that the original dentist hadn't actually filled the roots, he'd just stuffed them with little sticks he called "carriers" and filled the tooth over the top of them. He said that it was a cheap, easy "short cut" that some dentists take.  

After insurance, I'm looking at at least $800 out of pocket, probably more, for something that, if it had been done properly the first time, would have been a simple crown, instead of a complete retreatment of the tooth. Do you think the original dentist office should have to pay at least a portion of the endodontist bill?

This same office recently did a root canal on one of my teeth, and one of their titanium files broke off in the tip of the root.  The dentist chose to leave it there.  It took six weeks and a course of steroids to get the pain to stop.  He says leaving the file there shouldn't be a problem.  Should I have had that removed?  

I'm seriously starting to doubt the competency at this office.

I doubt that the tooth in question was #18, as that is the lower second molar, which erupts around 12 years. It is much more likely that it was #19, which would have been in her mouth since she was about 6 years old.

Carriers are either plastic or metal cones that are covered with gutta percha and are what is used to obturate canals in a proprietary system called ThermaFil. I personally do not use or like that system, but it is perfectly acceptable from a legal standpoint. Your dentist may not have done a good job with the treatment, but using ThermaFil is not prima facie evidence of poor dentistry.

Rotary files do fracture. It is unfortunate, but it happens to the best of us. Whether or not that is a problem depends upon when in the course of the treatment the file fractures. The object of endodontic therapy is to remove all the pulp and contaminants from the root canal space. If that is accomplished before the file breaks, then there is no problem. If the file breaks before that is accomplished, and the canal(s) cannot be cleaned, then it is a big problem. There is also no way to know if your pain was related to the file breakage or some other aspect of the treatment. Again, there are studies showing no difference in success with a broken file, but they would be cases in the first category.

If you need endodontics, you should be seeing an endodontist, in my opinion. Things can go wrong for any practitioner; that is a part of life. Many teeth present problems that just can't be solved. However, the incidence of problems is lower if you see an endodontist who does this every day for many years, and has advanced training, than for a general dentist. That is common sense, and there are studies to prove it. If you invested $70,000 in a BMW, and you had problems with the transmission, would you take it to the BMW dealer or Wal Mart to have it fixed? Many general dentists do a fine job, and I personally did mostly root canals as a general dentist for ten years before I did an endodontic residency. Still, general dentistry is enormously complex; physicians are not called upon to do every specialty in medicine. They either refer to the appropriate specialist, or they concentrate their efforts in one area. I think this is the model we should be following in dentistry as well. I know my brain isn't big enough to know everything about every specialty in dentistry; I have enough trouble keeping up with endo!


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Frederick R. Liewehr DDS, MS, FICD


I can answer your questions about root canal therapy in general. PLEASE DO NOT ask me to diagnose your particular problems or recommend treatment as I cannot do this without examining you and seeing your x-rays.


I am a Board-certified endodontist, former university department Chairman, teach dental residents, and have a private practice.


J of Endodontics, Endodontics and Dental Traumatology, O,O,O, Military Medicine, Medical Bulletin, J of Dental Education

DDS, MS (Oral Biology), certificate in Endodontics

Awards and Honors
Surgeon General's "A" Designator, Fellowship ICD, Order of Military Medical Merit

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